Oil circuit breaker



Feb. 28, 1933. 1, SLi-:PIAN

OIL yCLFCUIT BREAKER Filed DeC 3, 1929 INVENTOR Josep/1 S/e/o/a n.

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Pimm-l Fears, 1933 l 1,899,643

OIL CIRCUIT BREAKER Application ledbeceinber 3, 1929. Serial No.411,271.

My'invention relates to circuit interrupters the bubble, formedabout thearc, to reducev and particularly to circuit interrupters of its Isize toa bubble of small diameter having the oil-immersed type. its surface ofoil close to the arc core.

ne object of m invention is to provide It is a further object of myinvention to an arc path, estab ished in the above-menprovide meansabout the arc path of the 50 tioned type of structure, with means forreabove-mentioned structure that shall retain taining a portion of thequenching fluid in a portion of the quenching liquid available intimateengagement therewith throughout about the arc core as the gas bubbleabout the length of the arc path. the core is expanded beyond the means.

Alternating current arcs established under For a more completeQunderstanding of 55 oil, or in the presence of other suitableiluids, thenature and objectsv of my invention, refare extinguished within ashorter length of erence should be had to the following detime than arearcs having like current and scription, taken in conjunction with theacpotential that are established in the absence companying drawingwherein: 0f these fluids. I have discovered that the Figure 1 is adetailed view, artly seco tendency for the arc to extinguish morereadtion and partly in elevation, o a circuit inily in the gas bubbleformed under the fluid, terrupter embodying my invention; is due to thecontinuing decomposition of the Fig. 'A2 is a detailed v1ew, partly insection Huid at the boundary of the bubble, and and partly in elevation,of a circuit interthe continuing r evolution of gas at a hi h ruptershowing a somewhat different em- 05 rate. This gas passes turbulentlyinto t e bodiment of the arc extinguishing device of arc space, andforms relatively cool centers .Fi 1. into which ions from the currentcarrying lIy invention comprises, in general a casrtions of the arcspace diffuse and recoming 1, containingan arc quenching hquid 2 ine.VThis passing of the ions outwardly and supportin a cover 3, that isclamped 70 from the hot, highly ionized, current carrythereon by bots 4.The cover 3 supports ing portions of the arc space, into theinterconductin bushings 5 and 6 in a well knownmingled,relatively,cold,andunionizedgases, manner, t e portion of thebushings .subblown in,turbulently from the decomposing merged in theliquid 2, being employed to Huid, continues during the extinction periodSupport the stationar contact members7 and 75 following a current zeroin its cycle of alter- 8, respectively. A lig rod 9, extends throu h,nation, and causes the arc space to recover the cover 3, and is attachedexteriorly of t e dielectric strength, more rapidly than would `casing1, to an operating mechanism (not occur, if this blast of un-ionized gasfrom shown) and supports on its opposite ends, the bubble walls did notexist. within the casing 1, a conducting member 11 8 It is to Tbeexpected then, that in. order to that bridges the stationar contactmembers increase the tendency of the gases to extiu- 7 and 8 when thelift r 9 is moved to its Uuish the arc, the rate of generation of gasuppermost position. by decomposition of the fluid should be in-Referring to-Fig. 1, the contact members 7 creased, and this gas shouldbe passed turand 8 have a supporting plate 12 and 13, 85 bulentlythrough the arc stream. respectively, attached to the members by It isanother object of my invention to probolts 14. The members 12 and 13support,

" vide a chamber associated with an are terby means of bolts 15, aplurality 0f washers minal of a circuit interru'pter of the above- .orplates 16 that are positioned transverse to mentioned type, that shallreceive the gas in the arc path between the brldging member gas bubble18, that forms thereabout, has

expanded beyond the vopening 17 in -the washer.

In the present arrangement lof the luid containing plates, when gas isgenerated by the are the luid is pushed away from the arc path by thelarge gas bubble 18 that forms thereabout. The plates 16 are supportedwith their central opening 17 alined with the arc path, and as thebubble is expanded beyond the openings 17, the arc engages the exposedsurfaces of the plates 16. y

In Fig. 2 a somewhat different arrangement is illustrated for retainingthe fluid in close proximity to the arc path. The terminals 19 and 21 ofthe circuit interrupter are hollow and are directly connected to the gasfilled chambers 22 and 23, respectively. The lift rod 9, supports thebridging member 24. that is provided with spring pressed contact members25 or engaging the terminals 19 and 21, respectively, to complete anelectric circuit through the terminals 5 and 6.

The object, of so constructing and locating rthe chambers 22 and 23, isto provide receptacles for receiving the gases generated by thedecomposition of the fluid in order to pre- 'vent the formation of largegas bubbles about the arc paths. This arrangement leaves the fluid'surface of the bubble in intimate relation with the arc core, and freshgas will be continuously liberated through the decomposition of thefluid.

The gas in the container 22 and 23, while maintained at the samepressure as the surrounding liquid 2, oflers less resistance to the'pressure of the gas in the bubble because of its relative lack ofinertia. The development of the bubble takes place at. avery rapid rateand because of the inertia of the liquid surrounding thel chamber thepressure of the as therein will react on the gas in the cham er and willmove thereinto rather than displace the liquid 2, which could not beaccomplished instantaneously because of its inertia.

The operation of my extinguishing device will now be explained. When thebridging member'11 of Fig. 1 is moved to its lowermost or open position,arcs will be established ciin the liquid 2 between its ends and thestationary contact members 7 and 8, respectively. The liquid 2 about thearc path will be bontinually decomposed by the heat of the arc and thegases so generated will move ,turbulently into the arc path, and mixingwith highly ionized portions which are carrying current, will withdrawions, as a result of the diffusion, from the highly ionized parts intothe un-ionized colder parts of, the gas which have just been introducedinto the space.

. In structures heretofore employed in the art, because o the rapidaccumulation of gas adjacent the arc, the surface of the gas bubble wasquickly moved outwardly from the arc to a position, in which the liquiddecomposes at a much reduced rate, and this gas, being spread over alarger section, was less eiective in deionizing the current carryingportions of the arc.

In my present arrangement, as illustrated in Fig. 1, portions of thewashers or plates 16, having holes 17 aligned with the arc path, aremaintained adjacent tothe arc and supply liquid in its immediatevicinity, even though the bubble has been expanded beyond the plates.The liquid retained by the plates 16 will be decomposed by the arc andfresh ases will be continually given oli and pass turbulently throughthe highly ionized current carrying portions of the bubble.

By retaining the liquid in intimate engagement with the arc at alltimes, the gas evolution is accelerated, and the intermingling with thepreviously ionized gas is rendered `more thorough and intimate. Hence,at the moment of current zero,.there will be a very rapid deionizationof the highly ionized portions of the arc path,4 because of the passageof the ions into the cold un-ionized intermingled gases. ionization ofthe current carrying-path the arc does not reignite.

Referring to Fig. 2, as the bridging member 23 is moved to openposition, an arc will be drawn between the contacts 25 and contacts 19and 21, and the gas .will be given oli in the same manner as explainedhereinbefore. In order to prevent the gasbubble from growing to anundesirable dimension that would materially lessen the rate ofdecomposition of the oil, I have provided chambers 22 and 23 for drawingoli the gas as the pressure and size of the bubble increases and therebyretain the surface of the resulting small bub ble in close proximitytothe arc core. Thus, although the bubble around the arc remains small,there is an increased passage of gas through the arc.

As a result of this rapid dei' It is to be understood that when-thewordsoil, liquid, and fluid are employed 1n the specification that thebroad interpretationthereof is intended and that oil, carbontetrachloride and other well known arc quenching liquids, as well asgases, such as hydrogen, are intended to fall within the purview of thepresent invention. i It will thus be seen that I have a device forretaining a liquid in close proximity to an arc path in order that itmay be available for decomposition by the arc, to

provided supply a! gas to the arc path, for deionizing e currentcarrying portions of the arc space. This arrangement is novel in thatfresh deionizing gases that vpass through the arc core are given off atan increased rate.

y invention is further novel, in that, the receptacle provided fordrawing olf a portion of the generated until current zero, to reduce thesize of the bubble about the arc, so that fresh gas may be. liberatedand rapidly passed into the arc ath.

hile I have described particular lmeans comprising plates of insulatingmaterial to retaln fluid in immediate proximity to the arc path, it willbe recognized that )this is onl by way of illustration of generalprincip es and that my invention is not limited to that particulardevice, but comprehends any means of retaining in spatial distributionalong the sides of an arc path, a substance adapted toemit a vapor whenin contact with an arc. In the'case of fluid arc extinguishing agents,enclosures of high resistance material adapted to retain the fluid inchannels or pockets or through capillary forces-are effective. It willalso be observed that the retained material may be a different substancefrom the insulating luidsurrounding "I through said Dco;

the contacts; the latter may even be ordinary il air 1n such case; andthat solid substances,-

capable of furnishing vapor to the arc when brought in contact therewithmay compose or be'disposed upon the All similar embodiments principlesare of the following claims.

I claim as my invention:

1. In an arc-extinguishing body of fluid, a openings therein,

of its fundamental structure, a plurality of plates having means forcausing an arc o nings, said plates being of Fuller board or retainingsaid liquid by capillary attraction in contact with the arc and beingspaced substantially uniformly along the whole length of the arc.

2. In a circuit interrupter, a body of liquid, means for causing an arcin said liquid, means of Fuller board positioned along the length of thearc path for retaining said liquid and feeding it into the arc path assa1d liquid is acted upon by the arc to supply gas to extinguish thearc, and vent-ing means pernitting lateral fiow of said gas from said ymeans of porous insulating material along the length thereof.

3. In a circuit interrupter, ing a bod of `liquid therein, separablemeans for rawing an arc in said liquid, an arc extinguishing structureof plates of porous insulating material positioned 'substantiallyuniformly along the length of the aro path, said plates retaining saidliquid and feeding it into the arc path as it is decomposed tocontinuously supply gas, retains the gas length of the arc supportingwalls.`

intended to be within thescope b a con tancr ha vincluding a stack t gasto flow through the arc to extinguish it, and venting passages extendinglaterally from the arc path at points along substantially the wholelength thereof, said venting passages being open at their outer endspermitting said .gas to flow laterally way from said stack of plates,and said cont iner having a cross-sectional area several times greaterthan the cross-sectional area of said stack of plates, whereby saidcontainer does not materially impede the lateral flow of gas fromu saidstack.

4. In a circuit interrupter, a container having a body of liquidtherein, separable means for drawing an arc in said liquid, an arcextinguishing structure including a stack of plates of porous insulatingmaterial positioned substantially uniformly along the path, at spacedintervals, said plates retaining said liquid and feeding it into the arcpath as the liquid at the surfaces of said plates adjacent the arc pathis decomposed to continuously supply gas to flow through the arc toextinguish it, said spaces between said plates forming venting passagesextending laterally from the arcpathatpoints along substantially thewhole length thereof, and said spaces being openlat the outer edges ofsaid plates permitting said gas to ow laterally away from said stack oflates and preventing high gas pressures eing built up in said 'arcextinguishing structure, and said container having a cross-sectionalarea severaltimes greater than the crosssectionalarea of said stack ofplates, wherey said container does not materially impede the lateralflow of gas from said stack.

5. In a circuit interrupter, a container having a body of liquidtherein, separable means for drawing an arc in said liquid, an arcextinguishing structure including a stack of plates of porous insulatingmaterial positioned substantially uniformly along the length-of thev arcpath, said plates retaining said liquid and feeding it into the arc pathas the liquid at the surfaces of said plates adjacent the-arc path isdecomposed to continuously supply gas to flow through the arc toextinguish it, said arc extinguishing structure having venting passagesextending laterally from the arc path at points along substantially thewhole length thereof, and said Ventilating passages being open at alltimes at the outer edges of said plates and there being a large spacebetween the edges of said plates and said container permitting said gasto, flow laterally away from said stack of plates and preventing highgas pressures being built up in said ure. A

6. In a circuit interrupter, an arc extinguishing structure including aplurality of plates of porous absorbent insulating material, alignedopenings through said plates, means for drawing the arc with the portionarc extinguishing strucally from the openings thereof which is initiallydrawn in said openings, a container havinga body of liquid thereinsurrounding said are extinguishing structure, venting means extendinglaterthrough the plates in which the arc plays to an outer edge of theplates, and said container having a cross-sectional area several timesgreater than the area of said plates. 7. In a circuit interrupter, anarc extinguishing structure including a plurality of plates of porousabsorbent insulating material, aligned openings vthrough said plates,means for drawing thearc including a 'contact member movable throughsaid openings, said Contact member having substantially the same widthas said openings, a container having a body of liquid thereinsurrounding said arc extinguishing structure, venting means extendinglaterally from the openings through the plates in which the arc plays toan outer edge of the plates, and said container having a cross-sectionalarea several times greater than the area of said plates.

8. In a circuit interrupter, a pair of contacts one of which is movableand between which the circuit through said interrupter is initiallybroken, an arc extinguishing structure including means of insulatingmaterial having an opening therethrough in which the arc caused by theinitial break of the circuit plays, said means of insulating materialhavabsorbent material along said opening for JOSEPH SLEPIAN.

ing portions at the edge of said opening extendingfsubstantially to thepath f movement of said movable contact member, an outer casing for thecircuit interrupter enclosing said arc extinguishing structure, saidouter casing having a cross-section several times greater than thecross-section of said arc extinguishing structure, said means ofinsulating material including portions of absorbent material along saidopening for the arc, said absorbent material having retained therein aliquid which gives oi a large volume of gas'when acted upon by the arc,and Ventilating means extending from said opening for the arc caused bythe'initial break of the circuit to the space enclosed by said outercasing.

' 9. In a clrcuit interrupter, a pair of contacts one ofwhich is movableand between Whlch the circuit through said interrupter is initiallybroken, an arc extinguishing structure includingva stack of plates ofinsulating material, said stack having an opening therethrough in whichthe arc caused by the initial break of the circuit plays, said openinghaving portions of a wid@ not substantially greater than the width ofsaid movable contact member, an outer casing for the c1r cuitinterrupter enclosing said are extinguishing structure, said outercasing having a cross-section several times greater than thecross-section of said arc extinguishing strueture, some of said plateshaving portions of

